Code to run analysis and generate figures for McNeall et al. (2023) “Constraining the carbon cycle in JULES-ES-1.0”
## Warning: replacing previous import 'lifecycle::last_warnings' by
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## Warning: replacing previous import 'lifecycle::last_warnings' by
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Are there hard thresholds after which the model always fails? (Question from review comments). Run failures are in t
It’s important to remember that the design of the experiment is multiplication factors of the original parameters. This might be important for the “hold” value in a sensitivity analysis, as the “standard” value and the median value of the ensemble will not be the same.
Global mean for the 20 years at the end of the 20th Century. There is still a significant low bias on cVeg output.
Just under a third. Points at a significant model discrepency in cVeg
Of the 400 members of the wave01 ensemble, 128 pass Andy Wiltshire’s Level 2 constraints.
## [1] 128
## [1] 0.32
Section 2.5 in Friedlingstein et al. describes how the land carbon sink is estimated. IPCC AR6 Chapter 5 states: “The net land carbon sink is taken as net biome productivity (NBP) and so includes any modelled net land-use change emissions. Further details on data sources and processing are available in the chapter data table (Table 5.SM.6).”
The GCP says: “The land sink is the average of several dynamic global vegetation models that reproduce the observed mean total land sink of the 1990s.”
AR6 Chapter 5 states: "The land carbon cycle components of historical ESM simulations show a larger range, with simulated cumulative land carbon uptake (1850–2014) spanning the range from –47 to +21 GtC, compared to the GCP estimate of –12 ± 50 GtC (Figure 5.23b).
Proportion of the initial range of model output that is covered by level 2 constrained ensemble (%):
## npp nbp cSoil
## 26.6 55.1 48.3
## cVeg lai_lnd_mean rh_lnd_sum
## 23.5 60.9 26.0
## fLuc_lnd_sum fHarvest_lnd_sum treeFrac_lnd_mean
## 51.5 60.7 88.3
## shrubFrac_lnd_mean baresoilFrac_lnd_mean c3PftFrac_lnd_mean
## 85.4 52.9 58.0
## c4PftFrac_lnd_mean
## 43.9
## [1] 12.334